X-ray scatter represents the primary source of increased radiation dose and image degradation for patients in radiographic and tomographic imaging. Anti-scatter grids are used to improve clinically acquired planar radiographic studies. The improvement in image quality, however, is at the expense of a significant increase in patient dose, typically 100 to 500%. Tomosynthesis is a powerful pseudo 3-D imaging approach used commonly for low dose screening and diagnostic imaging in the breast and chest. Unfortunately, conventional anti-scatter grids cannot be used with tomosynthesis since multiple projection angles required for imaging. We have developed a scatter reduction technique applicable to tomosynthesis imaging which can actually also potentially reduce patient dose. The approach uses a radio-opaque grid with sparsely placed holes placed between the x-ray source and subject. X-rays are fired through the grid and a scatter image can be acquired. This scatter image can then be subtracted from the conventional projection images. The primary sampling scatter correction (PSSC) technique is especially well suited to our carbon nanotube enabled stationary tomosynthesis imaging hardware. The goal of this project is to design and implement this PSSC approach for stationary chest tomosynthesis (s-DCT). We will evaluate the image quality through recruiting patients with known lung lesions and performing both a PSSC and s-DCT scan. We will then evaluate the image quality of the PSSC chest tomosynthesis studies with radiologist readers.